Expansion joint



Jan. 3, 1928. 1,654,793

E. B. COWEN EXPANSION JOINT Filed Sept. 8, 1926 RUBBER A5 PHA L T COTTON FIBER CLAY (on LIME) Patented Jan. 3,1928.-

UNITED STATES EsBoN IBEZZLE COWEN,

OF TULSA, OKLAHOMA.

- EXPANSION JOINT.

Application filed September 8 1926. Serial No. 134,333.

The-object of this invention is to furnish an expansion joint for concrete roads or sidewalks or other concrete structures, steel structures and like uses, to take up and care for the expansion in the concrete and steel of which the structures are manufactured by a solid joint which may be compressed without destruction or misplacement. This joint is intended to and will remain in place and will not be misplaced by oozing either from above or below the concrete and will remain in place between the joints of the steel structure and take up the natural expansion of the concrete or steel. This joint eliminates the use of steel or wooden strips between the joints and may be placed as the concrete is laid or as the steel work is erected. The joint is also intended to prevent the possibility of cracks between a joint caused by the oozing of the usual liquid joint containing material which liquefies when exposed to heat.

In the drawing annexed Fig. 1 is'a detail perspective view of my joint-strip;

Fig. 2 is a vertical sectional view taken therethrough.

My expansion joint consists of a composition of rubber, cotton fiber, clay or lime and high test asphalt. The rubber gives the joint elasticity and permits compression. The clay or lime and asphalt insure wearing qualities and the cotton fiber acts as a binder for the other three materials.

These ingredients are milled and mixed in the proper proportions as hereinafter set out on a special kind of machine made for that purpose and pressed out to make it a solid material, suflieiently rigid to hold its shape but sufliciently elastic to permit the compression necessary to take up the expansion to which concrete or steel is subject.

The expansion joints are manufactured from one-fourth to one and one-half inches in thickness dependent upon the heat or cold to which the structure is to be subjected and dependent upon the locality in which it is used. The joints may be made the width and length desired but in concrete road work we would make them of width equal to the thickness of the concrete work and from one foot to ten feet in length, but they may be the abutting concrete or steel will hold it inplace while the other side is made smooth in the manufacture so that the concrete or steel may work'more or less freely on that side. This method of manufacture of the joint, rough on one side and smooth on the other will have a tendency to prevent the tearing of the expansion joint by'the expansion of the concrete or steel between the sections or joints of which it is used. It will be understood that the cement of the roadbed will mold itself to the rough side of the slaband thus in a measure be interlocked with it so that the slab will rise and-fall with this section of the roadbed body, while the adjacent section of the roadbed body, since it is molded against the smooth side of the slab, will be free to rise and fall independently of the slab.

The above ingredients in my expansion joint are milled and mixed under a special process used by me and'in three grades to be used according to the nature of the work and the necessity of each case' to obtain the best results. The composition of the three grades of my expansion joint is as follows:

- Grade #1New or used rubber 30 pounds; asphalt 210 degrees 27 pounds; clay or lime 34 pounds; cotton fiber 9 pounds.

Grade #2New or used rubber 35 pounds; asphalt 210 degrees 48 pounds; clay or lime 12 pounds; cotton fiber 5 pounds.

Grade #3New or used rubber 40 pounds; asphalt 2.10 degrees 44 pounds; clay or lime 11 pounds cotton .fiber 5 pounds.

On account of cheapness, I may use in producing my product cast-oft tire casings and inner tubes. The casings are articularly desirable because they contain, invariably The the desired quantity of cotton fibers.

casings and tubes are put through shredders and grinders, well .known in the rubber trade, which step reduces the material to" very fine particles. I then add the high-test asphalt and clay (preferablyj what is known as guilders whiting), and then this mixture is put through the regular rubber-working machines known as the rolls. These rolls are first warmed up by applying steam thereto, and after this initial warming no further application of extraneous heat is needed, as the friction produces sufficientheat to keep the-mass in a semi-molten condition, this high degree of friction being caused by one roll traveling faster than the other, as usual in this class of machines. Cold water is run through these rolls to keep them at an even temperature of the desired desired width; and, subsequently, While still" Warm, it is cut into the desired lengths, and

degree. Atter the material is run through these rolls a suflicient number of times tothen laid aside to cool. WVhen cool, the slabs are stiff enough to be handled easily and, in order to prevent the slabs sticking together When piled or baled, they are desirably rolled in soapstone dust. lVhen reclaimed rubber is used in place of cast-ofi' tires and tubes, the process is identical with the foregoing except that the cotton lint is added to the mass at the time the body-forming material and the asphalt are added. I use hightest asphalt in order to obtain a high melting point. If a low-test asphalt were used, the suns ra s in hot Weather would melt the strip su ciently to cause the asphalt to run and thus be squeezed out of the joints and run over upon the surface of the road-bed by expansion of the sections of the road-bed; and then when the road-bed cools and contracts, the squeezed-out asphalt also cools andthus is prevented from running back into the joints.

I claim: A preformed expansion-joint-strip con- 'sisting of a mass of comminuted intimatelymixed rubber, cotton fiber, high-test asphalt and a body-forming wearing substance, the whole bein compacted to form a solid elastic slab suliiciently rigid to hold its shape.

Witness my hand this 1st day of September, 1926.

ESBON BEZZLE oowEN. 

